On Tue, Oct 17, 2023, at 10:48 AM, Christoph Anton Mitterer wrote:
> As Lawrence pointed out:
> $ set -u
> $ declare -A a
> $ echo ${a[k]}
> bash: a[k]: unbound variable
>
> Here it actually looks first at a (which turns out to be an associative
> array) and thus doesn't even bother to evaluate k, which makes sense of
> course, in order to avoid any side effects.
No. As I said earlier, the reason "k" is not expanded here is that,
for associate-array accesses, subscripts are NOT arithmetic contexts.
It is not some sort of optimization. Even if all relevant variables
are defined, "k" is not expanded:
$ set -u
$ k='1+2'
$ declare -A arr=([k]=foo [1+2]=bar [3]=baz)
$ echo "${arr[k]}"
foo
--
vq
